Coherent imaging fiber based hair removal device

ABSTRACT

A photoepilation device including a compact hand piece applicator and a portable electronics module for use in a non-medical setting. The hand piece, which contains no electrical signals, allows the user to focus on individual hair follicles by observing a magnified image provided on a semiconductor display. The image from the hand piece is transported to a remote CCD through a coherent imaging fiber, which also delivers the therapeutic energy pulse from a remotely located source to the localized target. Destruction of pluripotential follicular stems cells found in the hair bulb and bulge regions is possible via a single low power laser diode. Control of pulse width and spot size attains a range of fluence levels up to 85 J·cm −2 .

PRIORITY

This application claims priority to U.S. Provisional Application No.60/977,851, filed Oct. 5, 2007, the contents of which is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to methods and apparatus utilizingselective and extended photothermolysis for various cosmetic, health anddermatology conditions, particularly, to techniques using lower powerlaser diodes for the inexpensive manufacture of safe products that canbe used in non-medical facilities such as spas, salons and the home.

2. Brief Description of the Background Art

Electromagnetic energy, particularly in the optical band 400 nm to 1200nm, has been used for treatment of many skin related diseases as well asfor cosmetic procedures, such as, hair removal, spider veins, tattoos,port wine stains, and for skin rejuvenation and photodynamic therapy.Laser- and light-based removal of hair, both in men and women, is widelyaccepted as a successful approach. In today's market place manufacturershave focused toward three laser-based systems: 1) alexandrite (755 nm),neodymium-doped yttrium aluminum garnet (1064 nm), laser diodes (810 nm)and a broad band intense pulsed light source (IPL). Generally, allsystems provide reduction in the growth cycle of removed hair. Multipletreatments have been found to improve upon the longevity of the hairfree period. The endpoint for an acceptable treatment requires thedestruction of pleuripotential follicular stems cells and not merely theevaporation of the hair shaft.

Recent data suggests that the stem cells are to be found in upper bulband bulge regions of the hair follicle. Indeed there may be other areasnot yet identified. Laser hair removal (LHR) procedures must targetthese multiple locations of the stem cells responsible for hair growth.Several techniques have been developed for targeting the destruction ofcells. Laser ablation, not typically used for photoepilation, uses highenergy short pulses to raise the temperature of the cell above thatrequired for evaporation, however, the target and the absorber must becollocated. Selective photothermolysis (SP) exploits dissimilarabsorption coefficients of the photo absorbers and surrounding tissue.However, use of SP for destroying the stem cells responsible for hairgrowth is compounded because the photo-absorbing chromophore, melanin,is found both in the follicular stems cells and the epidermis. Melaninhas a broad absorption spectrum and is responsible for the pigmentationof the hair shaft and the skin. SP techniques are effective if theconcentration of melanin is higher, by a factor of five, in the targetarea. These techniques work particular well for dark hair on light skin.However, unavoidable absorption of photons in the epidermis leads toheat, which needs to be removed if damage to the epidermis is to beavoided. Consequently, innovative hand-pieces which chill the epidermisduring treatment have been developed.

Destruction of cells through thermal denaturing requires that targettemperature exceed 70° C. within the thermal relaxation time (TRT) ofthe tissue, for the hair shaft the TRT is in the range of 35 to 50 ms.Pulse widths exceeding the TRT permit diffusion of heat into surroundingtissue preventing the denaturing temperature to be reached, due to heatleakage. Typically, LHR devices target about 1 cm² area of the skin,which is bombarded with photons. Some photons are absorbed in theepidermis, while the remaining migrate, via scattering through thedermis and reach the melanin rich hair shaft and bulb region, whereabsorption leads to elevation of tissue temperature causing celldestruction. The photons scattered in the backward direction return backto the epidermis resulting in fluence levels, which exceed the incidentfluence.

Based on photon transport theory and clinical data an optimum set ofparameters can be established for a particular device. Unfortunately,these parameters are also very patient dependent and use of LHR devicesremains somewhat of an art.

A typical laser diode system will have a variable fluence between 20 to60 J·cm⁻², a pulse width in the range of 5 to 500 ms, and a treatmentspot size of ˜1 cm². The peak power of the source, which determines thesize of the LHR system, is proportional to the product of fluence andspot area and inversely proportional to the pulse width. For example, a100 □s pulse with spot area of 1 cm² requires a peak pulse power of 20kW for a fluence of 20 J·cm². Consequently, this leads to bulky andexpensive machines, which need full medical facilities for operation.While the large diameter reduces treatment time and increasespenetration depth into the dermis, it lacks the capability toselectively remove hair from a given area, i.e. reduce hair density.

Another approach for permanent hair removal is based on extendedselective photothermolysis (ESP). The target to be denatured can beseparated from the photo-absorber, known as the heat source. A closerstudy of the underlying thermal diffusive processes has led to the useof longer pulses to produce a hot spot in the melanin rich hair shaft.The longer laser pulse produces a hot spot which begins to heat thesurrounding tissue, including the hair bulb and bulge. The choice of thepulse width is determined by the TRT and the thermal damage time (TDT).Recent studies have indicated, particularly for techniques using thehair shaft for heat transmission, that a longer pulse width up to 1.5 smay be acceptable, substantially, decreasing the peak power requirement.Several LHR systems using laser diode arrays, with peak power up to 200W are now in the market.

Other procedures for efficiently using the available photons in LHRdevices include the use highly reflective and thermally conductiveapplications to the skin prior to laser treatment. Ultrasonic massagingof the epidermis increases the penetration of the dye into.Pre-treatments can be used vital any of the light-based techniques toenhance the efficacy of hair removal, but adds extra time and cost tothe treatment.

Weckwerth U.S. Pat. No. 7,118,563, the disclosure of which isincorporated herein by reference, discloses a rechargeable devicesuitable for providing therapeutic energy. However, the minimum spotsize of 0.25 cm² is too large for targeting single hair follicles andthereby causing a reduction in the peak power requirement and theirsystem lacks any imaging device for identifying treatment area.

Altshchuler U.S. Pat. No. 7,220,254, the disclosure of which isincorporated herein by reference, teaches how the existing technologycan be packaged into a self-contained hand-held device for the deliveryof therapeutic energy to a skin treatment area, which can be visualizedby an image capturing system integrated into the hand-held device. Thedevice combines discrete optical and electronic components to illuminatean area of the skin to facilitate imagining by a CCD/CMOS device. Theimaging and treatment optical paths are separated by means of the commonpractice of using a beam splitter. A more compact and user friendlyhand-held device, with few components, would be more desirable,particularly for the home market. In fact, in keeping with this concept,Altschuler et al. Pub. No US 2007/0198004. the disclosure of which isincorporated herein by reference, addresses some of the above problemsin disclosing a tethered hand-piece which may be more appropriate forthe home market. However, the said photo cosmetic device does notinclude an imaging capability and uses lower power EMR sources withprolonged exposure times. For hair removal they recommend power levelsin the range of 20-500 W, not attainable by a single laser diodes.

SUMMARY OF THE INVENTION

The present invention discloses a compact hand piece applicator for LHR,including a coherent imaging fiber (CIF); a fiber optic switch; opticalfibers for white light illumination; chilled air delivery system;imaging optics; and an extender for the treatment spot through scanning.The coherent imaging fiber serves a dual purpose: 1) provides an imageof the target area, for example, a hair follicle; 2) deliverstherapeutic energy from the remote optical source to the target. Thespatial cross-sectional distribution of the therapeutic laser energy canbe shaped by exciting appropriate pixels in the CIF, for example, acircular spot or a donut shaped spot. The hand-piece provides theability to alter the size of the target spot, which is expected to besmaller than the diameter of the hair follicle. The laser diode, with awavelength in the range 750 to 850 nm, provides a broad range of pulsewidths applicable to SP or ESP. The power level of the optical sourcecan be increased through the use of multiple single LDs or a singlelaser diode array. The fiber optic switch, which can be replaced by anoptical microphone, controls the delivery of the laser diode energypulse or pulses. The absence of electrical signals in the hand pieceoffers added safety to the home user. Further the invention includes aportable electronic system which provides all the controls necessary tooperate the system and to interface with other computing devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following detailed description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a block diagram of the portable laser hair removal system ofthe present invention;

FIG. 2 is a schematic of the fiber optic hand piece applicator of thedevice of FIG. 1;

FIG. 3 is a cross-sectional view of the optical switch of the device ofFIG. 1;

FIG. 4 is a cross-sectional view of a hair follicle with directillumination of the hair shaft according to the present invention;

FIG. 5 is a cross-sectional view of the hair follicle with directillumination of the inner root shaft using a donut beam according to thepresent invention;

FIG. 6 is a timing diagram for dual pulse treatment according to thepresent invention;

FIG. 7 is a schematic of a dual laser diode illumination schemeaccording to the present invention;

FIG. 8 is a schematic for producing a scanning spot on the targetaccording to the present invention; and

FIG. 9 is a schematic of a preferred embodiment of the fiber optic handpiece applicator according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following detailed description of preferred embodiments of theinvention will be made in reference to the accompanying drawings. Indescribing the invention, explanation about related functions orconstructions known in the art are omitted for the sake of clearness inunderstanding the concept of the invention, to avoid obscuring theinvention with unnecessary detail.

The present invention discloses a portable an inexpensive apparatus forlocating and capturing the image of a small treatment area, typically,about 250 microns in diameter. Further more the said imaging hand piece,typically less thin 15 mm in diameter, provides for a means to deliveroptical energy from a remote source to the target area, preferablysmaller than the image size. The small size the hand piece isparticularly useful for treatment areas that require a reduction of thehair density and not indiscriminate hair removal. In a preferredembodiment, the hand piece is mounted on a robotic arm for automatedlaser hair removal.

Additionally, the small spot can be scanned across the target area tosynthesize a large treatment spot. Referring to FIG. 1 the miniaturehand piece applicator (HPA) 100 is an integral part of the flexibleumbilical cord 101, which connects to an electronic console 102. The HPAcan be operated either manually or as part of a robotic arm forautomated treatment. In the manual mode, the HPA is moved along thesurface of the treatment area 103, while viewing the color image 104 ona display screen 105, until a particular target 106, for example a hairfollicle, is located. At this point the image can be captured and storedin an embedded processor system 107. The imaging system illuminates thetarget area, transports the image formed at the distal end 108 of thecoherent imaging fiber 109 to its proximal end 110, and captures theimage using a CCD/CMOS device 111. Illumination of the target 103 isachieved by coupling the output from white light emitting diodes 112 and113 to the proximal end of multimode optical fibers 114 and 115, whichtransport the light to the HPA through the umbilical cord. The intensityof illumination is controlled through drive assembly 116. The microlensassembly in the HPA, see FIG. 2, forms a primary image of the target 106upon the distal surface 108 of the CIF. The magnification of the primaryimage is adjustable through the height of the baffle 117. The microlensassembly 118 forms a secondary image of the primary image on theproximal surface 110 at the surface of the CCD 111. The dichroic beamsplitter 119 separates the imaging path from the transmitting pathdiscussed below.

The transmitting path refers to the optical system responsible fordelivering the high energy therapeutic laser pulse (TLP) to thetreatment area. Part of this optical system uses the same said CIFdescribed above for capturing the image of the target. In the manualmode, transmission of the TLP is initiated by a user command, which isgenerated by an optical switch 120 mounted in the HPA Upon receiving thecommand signal 121 from the optical switch control module 122, the laserdiode driver 123 sends an appropriate current pulse the laser diode (LD)124, which is pigtailed to a fiber assembly 125. The distal end of thefiber assembly is terminated with a microlens assembly 126 whichprojects the image of the distal surface, via the dichroic mirror 119,on to the proximal surface of the CIF. The proximal image of the TLP istransported to the distal end of the CIF in the HPA. In this manner, theTLP is delivered precisely to the target with negligible energy leakagebeyond the treatment area. The pulse parameters are adjustable throughthe embedded processor system 107.

The optical switch, also discussed in regard FIG. 3, modulates anoptical signal to define its ON/OFF states. A modulated signal from thelight emitting diode (LED) control circuit 122 drives a LED 127 which ispigtailed to an optical fiber 128. During the ON state the modulatedoptical signal from HPA is returned back to the control module 122 viaan optical fiber 129 which is pigtailed to a photodetector 130,typically, a pin photodiode. The received optical signal is detected anda waveform 121 is sent to the laser drive module 123. The waveform 121generates the TLP with a preset width and contains a delay whichprevents generation of further pulses in the event that the opticalswitch in the HPA either remains depressed or is depressed in rapidsequence. This safety feature prevents the pulse rate from exceedingpreset limits. In a preferred embodiment, the optical switch is replacedby an optical microphone in which case the ON signal is generated by theuser voice command.

The HPA 100 also provides for chilled air to be directed at thetreatment area. The chilled area is delivered through two stainlesssteel micro-tubes 131 and 132 from a chilled source and controller 133.

Referring to FIG. 2A, which is a cross-section of the HPA 100, which isconstructed from a cylindrical stainless steel housing 200. Foraesthetic purposes the HPA may be further encased in a specializedmolding (not shown). The CIF 109 is located in the central region,surrounded by ring containing tubing and optical fibers as discussedbelow. The CIF, typically has a diameter of 700 microns and 50,000individual pixel elements each having a diameter of 4.5 microns. Thedistal end 111 of the CIF is positioned in the front conjugate plane ofthe microlens assembly 201. As illustrated the microlens assembly formsa magnified primary image of the target 106 on to the distal surface 111of the CIF. The primary image is transported to the proximal surface asdiscussed above. The image magnification can he controlled by adjustingthe height of the opaque baffle 117. Optical fibers 114 and 115 providewhite light illumination 202, to enhance the quality of the capturedimage. Stainless steel micro-tubes 131 and 132 are used for transportingchilled air to the target area. Stainless steel channel 203 is used forthe optical switch illustrated in FIG. 3, while stainless steel channel204 may include other sensors, for example, a thermistor for monitoringthe target temperature.

During the treatment mode the CIF delivers the optical energy to thetarget. As illustrated in FIG. 2 b, it is possible to define anyarbitrary spatial distribution 205 and 206 by exciting the appropriatepixels at the proximal surface 110 of the CIF. The microlens assembly201 produces the desired spatial image on the target. Optical energy isdelivered to the treatment area for the programmed precise time and thelaser diode disabled until the optical switch is enabled.

FIG. 3 is a cross-sectional view of the optical switch in the HPA. Twomultimode optical fibers 128 and 129 are mounted in the stainlessmicro-tubing 203. A modulated optical signal emanates from the distalend of fiber 128. In the OFF position, FIG. 3A, the optical signal 300enters a slab waveguide 301 and is lost. As illustrated in FIG. 3B, theON position, the optical signal 300 enters the slab waveguide 301, andsome of the optical signal leaves the slab waveguide and enters thefiber 129 and is detected by the photodetector 130 in FIG. 1. Theoptical switch defaults to the OFF position until switch is moved to theON position by the user. Activation of the switch will produce a TLP ofpreset width and repetition rate. This feature adds another layer ofsafety.

FIG. 4 shows a cross-section of the hair follicle 400, which resides inthe three layers of the skin: 1) the epidermis 401, 2) the dermis 402and 3) the hypodermis 403. During the anagen phase of the hair growthcycle capillaries 404 provide nutrients to the bulb region 405, whichencompasses the dermal papilla 406. During this phase of the hair growthcycle the bulb is located 2 to 4 mm below the epidermis. The hair shaft407 and the inner root sheath (IRS) 408 grow together from the bulbregion upward toward the sebaceous gland 409. Each of the variousfollicular compartments arises from the germinative cell pool at thebase of the hair bulb. The inner most layer of the outer root sheath(ORS) 410 provides the slippage plane. The ORS remains behind and iscontinuous with the epidermis. The IRS disintegrates just belowsebaceous duct and the sheath-free hair fiber exits the pilary canal411. The bulge region 412, the putative site of follicular stem cellsand the bulb contain melanocytes, which give the hair shaft its color.These regions are the primary targets for photothermolysis as theyexhibit a broad absorption spectrum in the visible and near infraredregions. Melanocytes are composed of eumalanin which is brownish-blackand phuemelanin which is reddish. Photons from the TLP need to bedelivered to these regions in order to cause cell destruction. SPmethods of photoepilation bombard a large area of the epidermis in orderto increase the probability of reaching the target areas. Photons in theTLP are lost due to reflection at the epidermis, absorption in theepidermis and scattering in the dermis. The probability of photonsreaching the intended targets is extremely low, requiring high surfacefluence values and large spot sizes. In addition, deeper targets such asthe hair follicle are only reachable at longer wavelength (750-1000 nm).However, the absorption of melanin drops of at longer wavelengths,requiring even higher fluences.

Decreasing the requirement for peak power through a reduced spot size ofthe TLP pulse is not a viable solution as the photons migrate out of thetarget zone very rapidly. Moving to a smaller spot size demands newdelivery methods for reaching the intended targets. We describe threeoptical delivery techniques which target individual hair follicles,typically with a spot size smaller than 10⁻⁴ cm². One of these is theESP which uses heat diffusion to reach the intended targets by creatinghot spots in easily accessible parts of the hair follicle, mainly thehair shaft. However, delivering the TLP directly to the hair shaft,which has a nominal diameter of 80 μm, requires precise spatiallocation. Imaging and sensor techniques have been proposed for achievingthis goal, but all the proposed solutions include scanning functionalityin the hand piece, something that should be avoided if the device is tobe target for non-medical facilities.

One possible strategy, illustrated in FIG. 4, is to illuminate the hairshaft with a Gaussian laser spot 413, with a diameter slightly smallerthan the hair shaft diameter. Typically, the hair shaft has a diameterof about of 80 μm and the pilary canal has an opening with a nominaldiameter of 200 μm. The hair shaft is a highly absorbing medium and hasno useful optical guiding properties. Wang, et al. made opticallow-coherence reflectometry measurements of longitudinal scans of darkand light hair. They reported that the refractive index of the hairshaft increase from 1.57 for blond hair to 1.59 for black hair. Fromtheir data the attenuation coefficient for black and blond hair wasestimated to be 34.5 mm⁻¹ and 3.2 mm⁻¹, respectively. From thesemeasurements, made at 850 nm, the effective penetration depths of 29 μmand 310 μm for the black and blond hairs, respectively was determined.These measurements clearly indicate, contrary to some claims, that thehair shaft is not an optical fiber waveguide. Thus, photons incident onthe hair shaft are absorbed within this short layer, causing a localizedhot spot 414. By using lower fluences and longer pulse widths (500 ms),the hair root area can be heated to denaturing temperatures by allowingthe heat to diffuse down the hair shaft as indicated by 415.

FIG. 5 shows a second illumination strategy, which deposits photons tothe melanin rich sites by using the optical guiding channel created bythe concentric structure of the hair shaft, the IRS and ORS. Entrance tothe three layer waveguide is through the pilary canal 411. The IRS,which is sandwiched between the ORS and the hair shaft, below sebaceousduct, has a refractive index that is larger than that of the ORS butlower than that of the hair shaft. The three layers form a leakywaveguide, with the photons being absorbed on the hair shaft surface 502and reflected from the ORS surface 501. The donut shaped TLP 500 ismatched to the size of pilary canal, which has inner diameter bounded bythe hair shaft and nominal ring thickness 30-40 μm. Photons enter thepilary canal 412, which may contain the oil substance excreted by thesebaceous gland and enter the IRS below the sebaceous duct and areguided through the leaky modes to melanin rich bulb region containingthe stem cells to be destroyed. As these photons travel in the IRS someare likely to be absorbed by the melanocytes in the bulge. The fluencelevels are expected to be lower as none of the incident photons areabsorbed by epidermis or the dermis. Consequently the epidermis shouldexperience minimum heat stress. In this configuration pulse widthsshould correspond to the TRT of the bulb region.

A third illumination strategy can be a combination of both the above. Ashort pulse width donut beam can be superimposed on the long pulse widthGaussian beam toward the end of its duration as indicated by the timingdiagram in FIG. 6. This strategy allows the hair shaft temperature to beelevated by the extended TLP directed at the hair shaft, followed by thedonut shaped pulse just prior to the termination of the Gaussian pulse.The Gaussian beam may have a pulsed width in the range of 100 to 500 ms,while the donut pulse width is between 5 and 50 ms. In principle, thetwo laser diodes may have different wavelength and deliver differentfluence levels, which could be matched for the hair color. Referring toFIG. 7 LD 701 is pigtailed to a single multimode fiber which forms thecentral part of the distal end 706 of the fiber optic bundle 705. LD 702is pigtailed to a fiber bundle 704 comprising of multiple fibers 707which are arranged in an annular pattern 708 in the distal end of fiberbundle 705. In this way LD 701 and 702 may either have identical ordissimilar spectral and power properties. The distal end 706 can beintegrated to the microlens 126 in FIG. 1.

There may instances when neither of the above strategies for deliveringthe TLP is acceptable and a larger spot is required. As discussed above,with reference to FIG. 2, it is possible to produce any arbitraryillumination shape. For example, an elliptical spot which increases thespot dimension along one axis, while keeping the area small could beused. However, there may be instances when this approach is also notadequate. In such situations a large treatment area can be synthesizedby scanning the small spot over the target area. Sharon, U.S. Pat. No.7,101,365, the disclosure of which is incorporated herein by reference,describes a manual means to pivot the entire hand piece to obtain alimited scan. While Altshuler (discussed above) and Zavisian, U.S. Pat.No. 5,860,967, the disclosure of which is incorporated herein byreference, include a 2-D scanning mechanism in the hand piece. Thepresent invention achieves the desired scanning of the target byscanning an image of the source at the proximal end 110 of the CIF.Referring to FIG. 8, dots 801 and 802 show two arbitrary positions ofthe TLP on the target surface 103. FIG. 8B indicates the position of thecorresponding source points on the proximal end 110 of the CIF. Thetarget scan path corresponds to the scanned source image on the proximalend. The scanned image can be generated in number of ways. For purposeof illustration FIG. 8C shows 2-D mechanical scanner using mirrors 803and 804. The laser source beam 805 bounces of the two mirrors to definea scan path 806. FIG. 8D illustrates an alternative means of obtainingthe source scan, using 1×N fiber optic switch. In other words, theoutput of the input fiber 807 can be directed to any one of the outputfibers 808 by means of, for example, a rotating concave mirror 809.Other types of switches may be used. The output fibers form the distalend 706 of the fiber bundle described in FIG. 7. An important differencebetween the Sharon and Altshuler schemes is that all the scanningcomponents are in the portable electronic module, none of the componentsare in the HPA. This ensures a compact and safe hand piece suitable forthe non-medical facilities.

There are certain situations when indiscriminate hair removal using alarge diameter spot is not desirable. As an example, for cosmeticpurposes, patients may require an alteration of the hair density incertain parts of the human anatomy rather than total hair removal. Forsuch applications a LHR system must be capable of targeting individualhair follicles. The HPA described above can be used on a roboticplatform to remove hair from any random location. One such embodimentwill include a 3-D vision system in capable of creating a digital map ofthe surface to be treated. Appropriate software algorithms that analysesthe hair distribution and hair angle will determine the optimum locationof hair follicles to receive the laser treatment. The information woulddrive the robotic arm to automatically complete the treatment. Safetyfeatures, built around limit switches, ensure that the high energy spotremains with the treatment area.

Another preferred embodiment of the HPA is illustrated in FIG. 9. TheCIF 109 is surrounded by plurality of multimode fibers 901 which areused for delivering high energy optical pulses to the hair follicle. Theoutput of these multimode fibers is combined into a single spot at theentrance to the hair follicle 106. A radially bi-focal lens 902 providesdisparate magnifications for the CIF 109 and the multimode fibers 106.The multimode fibers can be used to increase the target fluence by usingplurality of optical sources at the same emission wavelength, oralternatively sources with output at different wavelengths could becombined to enhance the efficacy of the treatment.

An example of the fluence calculation in a preferred embodiment is asfollows. An expected fluence F_(t) [J·cm⁻²] at the target spot of areaA_(t) [cm²] for an imaging system with magnification M_(t) is related tothe power P_(f) emanating from the pigtailed laser diode by Equation(1):

$\begin{matrix}{F_{t} = {\eta \; \frac{P_{r}\sigma_{T}}{A_{T}}}} & (1)\end{matrix}$

where η represents all the transmission losses from the output of fiber125 to the laser spot illuminating the treatment area 103 and σ_(T) isthe pulse width or duration of the optical energy pulse which can beeasily controlled between 100 μs to 1 s. Using a conservative estimateof η=0.85, P_(f)=200 mW, A_(t)=10⁻¹ cm², which is a typical diameter ofthe hair shaft, and σ_(T)=50 ms, we obtain F_(t)=85 J·cm². The fluencecan be easily controlled though a combination of the three parameters,P_(f), or σ_(T) or A_(T).

While the invention has been shown and described with reference tocertain exemplary embodiments of the present invention thereof, it willbe understood by those skilled in the art that various changes in fromand details may be made therein without departing from the spirit andscope of the present invention as defined by the appended claims andequivalent thereof.

1. A portable device for photo-inducing damage to cellular structuresfor hair removal, the device comprising: a hand piece provided with acoherent imaging fiber bundle, a plurality of optical switches, aplurality of multimode optical fibers, capillary tubing for transportingcoolant and an imaging lens; and an umbilical cord connecting to thehand piece.
 2. The portable device of claim 1, wherein the coherentimaging fiber bundle, together with an imaging lens, delivers opticalenergy, with high fluence, to a targeted hair follicle.
 3. The portabledevice of claim 2, wherein the coherent imaging fiber bundle alsotransports an image of the targeted hair follicle.
 4. The portabledevice of claim 1, wherein the coherent imaging fiber bundle includes acentrally located multimode fiber for delivery of optical energy, withhigh fluence, to a single hair follicle.
 5. The portable device of claim1, wherein the coherent imaging fiber bundle includes an outer ringcomprising a plurality of multimode fibers for delivering optical energyat a plurality of different wavelengths.
 6. The hand piece of claim 1,wherein the plurality of optical switches includes a plurality ofmultimode fibers for initiating a sequence of optical pulses from alaser diode source to a target area.
 7. The portable device of claim 1,wherein the coherent imaging fiber bundle, together with an imaginglens, captures a magnified image of a target area.
 8. The portabledevice of claim 1, wherein the plurality of optical switches includes aplurality of multimode fibers for initiating storage or displayedimages.
 9. The portable device of claim 1, wherein the capillary tubingtransports chilled air to cool an area of a targeted hair follicle. 10.The portable device of claim 1, further comprising a control module thatincludes: a beam splitter for separating the transmitting and receivingoptical signals traveling through the coherent imaging fiber bundle; animaging sensor, together with an imaging lens, for generating thedigital image; a display to show a real time image of a target area; alaser diode source imaged on to the coherent imaging fiber bundle via alens and an optical shutter; an optical switch; a plurality of whitelight emitting diodes connecting multimode fibers which transportbackground illumination to the hand piece; and a source of chilled air.11. A portable device for projecting two-dimensional spatial patterns toa treatment area, the device comprising: a hand piece that includes acoherent imaging fiber bundle, a plurality of optical switches, aplurality of multimode optical fibers, capillary tubing for transportingcoolant and an imaging lens; an umbilical cord connecting to the handpiece; and an optical system for generating the two-dimensional spatialpattern and projecting the pattern onto an end-face of fibers of thecoherent imaging fiber bundle.
 12. The portable device of claim 11,wherein a focused laser spot is scanned across an predefined area of thecoherent imaging fiber bundle via two deflecting mirrors.
 13. Theportable device of claim 12, wherein the predefined area is smaller than1 square millimeter.
 14. The portable device of claim 11, wherein anarbitrarily shaped object is imaged onto the end-face of the fibers. 15.An automated device for treating large target areas, the devicecomprising: a robotic platform; a miniaturized treatment hand piece; andan umbilical cord connecting the hand piece to a control module.
 16. Theautomated device of claim 15, wherein fasteners attach the treatmentsurface of the robotic platform.
 17. The automated device of claim 15,wherein the hand piece is secured into a housing of the roboticplatform.
 18. The automated device of claim 17, wherein three motorizedslides position the housing in any arbitrary location above thetreatment surface.